Thursday, August 03, 2006

The nation's leading public health organization - the American Public Health Association (APHA) - has grossly misrepresented the health risks of secondhand smoke to thousands of its members, informing them that even a minute level of exposure to secondhand smoke increases the risk of life-threatening disease.

In this month's issue of The Nation's Health - APHA's monthly newspaper - the organization claims that: "Any level of exposure to secondhand smoke puts nonsmokers at an increased risk for life-threatening disease, a federal report issued June 27 concluded."

The Rest of the Story

This claim by APHA is inaccurate in two different ways.

First, it is not true that any level of exposure to secondhand smoke puts nonsmokers at increased risk of life-threatening disease. This is a terrible misrepresentation of the scientific facts.

The truth is that high levels of chronic exposure to secondhand smoke increase the risk of heart disease and lung cancer among nonsmokers. Most of the studies which have reported an increased risk of these life-threatening diseases among nonsmokers have examined individuals with relatively high levels of exposure, either to spouses who smoked in the home or to smoking in the workplace.

None of these studies examined the effects of very low levels of secondhand smoke exposure, such as that encountered in outdoor spaces. There is simply no evidence to support an assertion that any level of exposure to secondhand smoke is sufficient to cause heart disease, lung cancer, and other life-threatening diseases.

The most imminent threat of a life-threatening disease from low levels of exposure to secondhand smoke is exacerbation of asthma. But this risk of life-threatening disease only holds for individuals with severe asthma and it's unclear that any level of exposure - including a brief whiff or two of smoke - would be sufficient to trigger a deadly asthma attack. I've seen some very sensitive asthmatics in my career, but by no means has APHA crafted their claim so narrowly so as to make it clear that it applies only to individuals with the most severe cases of reactive airways disease.

The second way in which the APHA claim grossly misstates the truth is that it states that the Surgeon General's report concluded that any level of exposure to secondhand smoke increases the risk of death, when in fact the report quite clearly concluded that substantial levels of chronic exposure to secondhand smoke increase the risk of life-threatening disease. Other than the case of severe asthmatics, the report offers no evidence, and presents no conclusion, that a very small amount of secondhand smoke exposure has been documented to increase the risk of life-threatening disease.

This misrepresentation of the science is unfortunate for several reasons.

First, it is going to unduly scare people. According to this article, virtually every one of us is at increased risk of life-threatening disease because practically all of us have already been exposed to some level of secondhand smoke.

Second, the article removes any incentive for nonsmokers to avoid exposure to secondhand smoke or for smokers to quit smoking. If they are already at risk of life-threatening disease by virtue of small exposures to secondhand smoke, then what is the point of avoiding further exposure, or of trying to reduce higher levels of exposure. According to the article, unless you can completely eliminate your exposure to secondhand smoke, you are going to face an increased risk of death. This hardly provides an incentive for the public to reduce their exposure. And it certainly would argue for smokers not to worry so much about quitting, especially if they are going to continue hanging out in environments where they are exposed to secondhand smoke.

Third, by obscuring the important relationship between dose and risk, the article undermines the process of priority-setting in secondhand smoke policy development. This type of communication might well lead public health advocates to worry about banning smoking in outdoor spaces - like beaches, parks, streets, and parking lots - rather than restricting their focus to places where people truly are at risk of life-threatening disease, like heavily polluted indoor environments where smoking is very prevalent, such as bars, casinos, and some restaurants.

But most importantly, the claim is simply false and it undermines APHA's credibility and its responsibility to adhere to high standards of scientific integrity in informing the public about population health risks. This I see as an ethical responsibility. And I think that APHA's code of ethics sees it this way as well.

Despite all of this, I do not completely blame APHA for this misrepresentation of the scientific conclusions of the Surgeon General's report. The underlying fault belongs to the Surgeon General's office for its own misrepresentation of the science. After all, it was the publicity put out by the Surgeon General, including his press release and accompanying materials, that misled the public into thinking that the report had concluded that any level of exposure to secondhand smoke entails an increased risk of potentially fatal disease.

The Surgeon General announced that his report had concluded that even a brief exposure to secondhand smoke causes heart disease and lung cancer, and repeatedly emphasized the dangers of any exposure to secondhand smoke, completely obscuring the well-recognized relationship between tobacco smoke dose and health risks.

APHA can hardly be blamed for misleading the public, when they were quite accurately conveying exactly what the Surgeon General communicated to the public (although not in his report itself).

This story demonstrates how quickly and how widely dangerous myths can spread when anti-smoking groups exaggerate and distort the science in order to create a dramatic emotional appeal in order to generate support for the anti-smoking agenda.

Taking a step back, it is quite remarkable how the misrepresentation of the science of secondhand smoke has spread throughout the anti-smoking movement in such a short time. When I first broke the story about the 30-minute claim put out by Action on Smoking and Health, I was under the impression that this was simply an errant statement by one tobacco control organization. Then, I found out that there were a couple of organizations involved. Before long, it became apparent that there were many groups - at last count, it was up above 80.

This just keeps getting bigger and bigger. Now it has spread to the Surgeon General's office and to the leading national public health organization. It is at the point where the anti-smoking movement, whether intended or not, is spreading widespread untruths about secondhand smoke. This is an abdication of our scientific integrity and public responsibility and a betrayal of the public's trust.

No comments:

About Me

Dr. Siegel is a Professor in the Department of Community Health Sciences, Boston University School of Public Health. He has 32 years of experience in the field of tobacco control. He previously spent two years working at the Office on Smoking and Health at CDC, where he conducted research on secondhand smoke and cigarette advertising. He has published nearly 70 papers related to tobacco. He testified in the landmark Engle lawsuit against the tobacco companies, which resulted in an unprecedented $145 billion verdict against the industry. He teaches social and behavioral sciences, mass communication and public health, and public health advocacy in the Masters of Public Health program.